如何在Python中使用空格将字符串填充到固定长度？

I'm sure this is covered in plenty of places, but I don't know the exact name of the action I'm trying to do so I can't really look it up. I've been reading an official Python book for 30 minutes trying to find out how to do this.

我确信这很多地方都有,但我不知道我正在尝试的动作的确切名称,所以我无法真正查找它。我一直在阅读官方的Python书30分钟,试图找出如何做到这一点。

Problem: I need to put a string in a certain length "field".

问题:我需要在一定长度的“字段”中放置一个字符串。

For example, if the name field was 15 characters long, and my name was John, I would get "John" followed by 11 spaces to create the 15 character field.

例如,如果名称字段长度为15个字符,而我的名字是John,我会得到“John”后跟11个空格来创建15个字符的字段。

I need this to work for any string put in for the variable "name".

我需要这个用于为变量“name”输入的任何字符串。

I know it will likely be some form of formatting, but I can't find the exact way to do this. Help would be appreciated.

我知道它可能是某种形式的格式化,但我找不到确切的方法来做到这一点。帮助将不胜感激。

6 个解决方案

#1

This is super simple with format:

格式非常简单:

>>> a = "John"
>>> "{:<15}".format(a)
'John           '

#2

You can use the ljust method on strings.

您可以在字符串上使用ljust方法。

>>> name = 'John'
>>> name.ljust(15)
'John           '

Note that if the name is longer than 15 characters, ljust won't truncate it. If you want to end up with exactly 15 characters, you can slice the resulting string:

请注意,如果名称超过15个字符,则不会截断它。如果您希望最终得到15个字符,则可以对结果字符串进行切片:

>>> name.ljust(15)[:15]

#3

string = ""
name = raw_input() #The value at the field
length = input() #the length of the field
string += name
string += " "*(length-len(name)) # Add extra spaces

This will add the number of spaces needed, provided the field has length >= the length of the name provided

这将添加所需的空格数,前提是该字段的长度> =所提供名称的长度

#4

First check to see if the string's length needs to be shortened, then add spaces until it is as long as the field length.

首先检查字符串的长度是否需要缩短,然后添加空格,直到它与字段长度一样长。

fieldLength = 15
string1 = string1[0:15] # If it needs to be shortened, shorten it
while len(string1) < fieldLength:
    rand += " "

#5

name = "John" // your variable
result = (name+"               ")[:15] # this adds 15 spaces to the "name"
                                       # but cuts it at 15 characters

#6

Just whipped this up for my problem, it just adds a space until the length of string is more than the min_length you give it.

刚刚解决了我的问题,它只是添加一个空格,直到字符串的长度超过你给它的min_length。

def format_string(str, min_length):
    while len(str) < min_length:
        str += " "
    return str

#1